Variable laser aperture using a flex circuit

Abstract

A system for and a method of optical scanning which provide for focusing a light beam using one or more flex circuits, each flex circuit containing an aperture that is moved into or out of the outgoing optical path of a light beam via an electromagnetic mechanism. The electromagnetic mechanism includes a moving coil or moving magnet attached to each flex circuit for positioning the flex circuit aperture in or out of the outgoing optical path when the electromagnetic mechanism is actuated by an electric current. By positioning a greater or lesser number of apertures in the outgoing optical path, the final aperture size may be modified, thereby adjusting the focal location and depth of field of the light beam. Accordingly, the scanning system provides improved focusing characteristics, as well as an increased read range.

What is claimed is:  
     
         1 . An optical scanning system, comprising 
 a light source generating a light beam along an outgoing optical path toward an object to be scanned;    a first flex circuit having a fixed end and a free end with an aperture formed in the free end, the first flex circuit flexing so as to selectively position the aperture in or out of the outgoing optical path.    
     
     
         2 . A system according to  claim 1  further comprising a housing, wherein the fixed end of the first flex circuit is fixedly attached to the housing.  
     
     
         3 . A system according to  claim 2  further comprising a magnet attached to the first flex circuit between the fixed end and the free end, and a drive coil attached to the housing proximate the magnet, the drive coil selectively attracting and/or repelling the magnet when the drive coil is actuated by an electric current thereby moving the second end of the first flex circuit into or out of the outgoing optical path.  
     
     
         4 . A system according to  claim 2  further comprising a coil attached to the first flex circuit between the fixed end and the free end, and a magnet attached to the housing proximate the coil, wherein the magnet is selectively attracted and/or repelled by the coil when the coil is actuated by an electric current thereby moving the second end of the first flex circuit into or out of the outgoing optical path.  
     
     
         5 . A system according to  claim 1  further comprising second and third flex circuits successively positioned downstream from the first flex circuit, the second and third flex circuits each having an aperture formed therein that is selectively positioned in or out of the outgoing optical path for focusing the light beam.  
     
     
         6 . A system according to  claim 5  wherein each successive flex circuit in the outgoing optical path includes a smaller aperture than the previous flex circuit in the outgoing optical path.  
     
     
         7 . A system according to  claim 5  further comprising an electromagnetic mechanism engaging the flex circuits, the electromagnetic mechanism selectively moving at least one of the apertures into or out of the outgoing optical path when the electromagnetic mechanism is actuated.  
     
     
         8 . A system according to  claim 1  wherein the aperture is circular.  
     
     
         9 . A system according to  claim 1  wherein the aperture is slot shaped.  
     
     
         10 . A system according to  claim 1  further comprising a lens positioned in the outgoing optical path, the lens focusing the light beam toward the object.  
     
     
         11 . A system according to  claim 1  further comprising a scanning assembly positioned in the outgoing optical path, the scanning assembly scanning the light beam toward the object.  
     
     
         12 . A system according to  claim 11  wherein the scanning assembly comprises a dithering mechanism having a scan mirror that is pivoted over a scan angle.  
     
     
         13 . A system according to  claim 11  wherein the scanning assembly comprises a rotating polygon mirror.  
     
     
         14 . A system according to  claim 1  further comprising 
 an optical collector positioned in an incoming optical path for collecting light reflected off of the object;  
 a detector positioned in the incoming optical path downstream from the optical collector for detecting light collected by the optical collector.  
 
     
     
         15 . An optical scanning system, comprising 
 a light source generating a light beam along an outgoing optical path toward an object to be scanned;    a flex circuit having a first fixed end and a second end with an aperture formed therein for focusing the light beam toward the object;    an electromagnetic mechanism engaging the flex circuit, the electromagnetic mechanism selectively moving the second end of the flex circuit into or out of the outgoing optical path.    
     
     
         16 . A system according to  claim 15  wherein the electromagnetic mechanism comprises a magnet attached to the flex circuit and a fixed drive coil proximate the magnet.  
     
     
         17 . A system according to  claim 16  wherein the fixed drive coil is adapted to selectively move the second end of the flex circuit into or out of the outgoing optical path when the drive coil is actuated.  
     
     
         18 . A system according to  claim 15  further comprising a lens positioned in the outgoing optical path for focusing the light beam to a given distance.  
     
     
         19 . A system according to  claim 15  further comprising 
 an optical collector positioned in an incoming optical path for collecting light reflected off of the object;  
 a detector positioned in the incoming optical path downstream from the optical collector for detecting light collected by the optical collector.  
 
     
     
         20 . A method of optical scanning comprising the steps of 
 generating a light beam along an outgoing optical path;    focusing the light beam with an aperture formed in a first flex circuit;    selectively positioning the aperture in or out of the outgoing optical path by flexing the first flex circuit;    directing the light beam toward a target object.    
     
     
         21 . A method of optical scanning according to  claim 20  further comprising positioning the aperture in or out of the outgoing optical path via an electromagnetic mechanism.  
     
     
         22 . A method of optical scanning according to  claim 20  further comprising focusing the light beam with second and third flex circuits each having a smaller aperture than the previous flex circuit in the outgoing optical path.  
     
     
         23 . A method of optical scanning according to  claim 22  further comprising selectively moving at least one of the apertures into or out of the outgoing optical path via an electromagnetic mechanism when the electromagnetic mechanism is actuated.  
     
     
         24 . A method of optical scanning according to  claim 20  further comprising focusing the light beam toward the object with a lens positioned in the outgoing optical path.  
     
     
         25 . A method of optical scanning according to  claim 20  further comprising 
 collecting return light from the target object with an optical collector;  
 detecting the collected return light with a detector.